Document WO2010/014001 describes a breast scanner having a positioning device, which latter comprises a frame supporting at least two positioning components—embodied as positioning plates—which define between them a receiving space for a breast of a person, which breast is to be scanned. The breast to be scanned can be introduced into this receiving space in an intended direction of introduction. At least one of the positioning components is placed movably on the frame in a first direction substantially towards another positioning plate of the at least two positioning components. The positioning components are arranged to touch, for example to compress the breast if placed between the positioning components. The known scanner further comprises a gamma camera, which is arranged to portray a volume in the receiving space on the basis of high-energy radiation, especially gamma radiation, emitted by the breast.
The gamma camera of the said known scanner comprises a plate-like collimator part, which is provided with at least a first multitude of focused pinholes, each having an individual field of view, i.e. part of the object which is imaged through the pinhole, wherein the individual fields of view of the first multitude of pinholes define a common central field of view as that part of the space which is seen through each of the first multitude of pinholes. The gamma camera further comprises a gamma-sensitive detector, which is arranged to receive images from the collimator. The plate-like collimator part is movable in a plane which is substantially parallel to one of the positioning components and is movable in that plane, preferably in mutually perpendicular directions in that plane. The scanner further comprises a collimator moving device, which is arranged to move the plate-like collimator part in that plane in a controlled manner.
This scanner, known from WO2010/014001, has the drawback of an unfavourable relationship between, on the one hand, a relatively large detector surface, necessary to make a scan of the desired volume, and, on the other hand, good sensitivity and resolution, especially if a part of the breast is scanned. This results in an uneconomical use of the difficult to produce and expensive detector material, which is a factor in preventing the use of such scanners on a larger scale.